Metro M4 Airlift not seeing sensors over I2C (Qwiic Shield)

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Infinite
 
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Metro M4 Airlift not seeing sensors over I2C (Qwiic Shield)

Post by Infinite »

Hi all,

I hope everyone is keeping well. I’ve made a weather station using an Uno R3 and SCD-30 CO2 Sensor. Using the Qwiic system it shows data on an OLED and logs the data to an SD Card. This bit has worked pretty well and am happy with it.

Additionally I can make a Metro M4 Airlift talk to Adafruit IO and do examples such as count, and that bit has been great step forward.

Now I want to use the same sensors with the Metro M4 Airlift to display the data on Adafruit IO, but for the life of me I can’t make the Metro M4 Airlift see any of the sensors over I2C. I have spare Co2 Sensors, M4 Airlifts and cables and have tried iterations to rule out any hardware problems. But I keep coming up short.

I’m using the IDE and have used both the example adafrui_SCD-30_test and also an Arduino I2C Scanner sketch but can’t see any hardware connected via I2C.

Any advice would be most welcome.

The configuration is:
M4 Airlift > Sparkfun Qwiic Shield > SCD-30 CO2 Sensor > SD Logger + OLED
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dastels
 
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Re: Metro M4 Airlift not seeing sensors over I2C (Qwiic Shie

Post by dastels »

From the schematics, it looks like the shield uses A4 & A5 as the I2C signals, whereas the Metro uses The UNO R3 spec with separate I2C pins (on the far corner of the board from A4/A5. If you cut the connection from A4/A5 and connect them to HV_SDA and HV_SCL, respectively, you should be good. The shield has a row of pads parallel to the headers so it should be straightforward to sever the trace between them (pad and header) and wire them to SDA/SCL. See the bottom of the shield: https://cdn.sparkfun.com//assets/parts/ ... 352-03.jpg.

Schematics:
QUICC shield https://cdn.sparkfun.com/assets/5/1/a/3 ... no_v10.pdf
Metro M4 https://learn.adafruit.com/assets/53093

Dave

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Infinite
 
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Re: Metro M4 Airlift not seeing sensors over I2C (Qwiic Shie

Post by Infinite »

Amazing!

You were right on the money, I can’t believe I missed that. A quick rewire and it works like a charm.

Thank you

Results:

“Scanning...
I2C device found at address 0x2A !
I2C device found at address 0x32 !
I2C device found at address 0x3C !
I2C device found at address 0x40 !
I2C device found at address 0x48 !
I2C device found at address 0x61 !
Done
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dastels
 
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Re: Metro M4 Airlift not seeing sensors over I2C (Qwiic Shie

Post by dastels »

Awesome!

Dave

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